provide a concise error message from the metrics command when PMU is not available

[harp-intel]

Error: 

broker1               ⣯  Error: failed to load metadata: failed to determine if fixed-counter instructions is supported: exit status 255 : failed to determine if fixed-counter cpu-cycles is supported: exit status 255

broker2               ⣯  Error: failed to load metadata: failed to determine if fixed-counter cpu-cycles is supported: exit status 255 : failed to determine if fixed-counter instructions is supported: exit status 255

The brokers here are ICX (m6i.4xlarge) nodes in AWS

Pre-check for PMU requirement so that a better error message can be presented to the user.